The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
Generally, a heat exchanger is installed in an automotive application in order to exchange heat between an internal fluid flowing through internal passages and an external fluid flowing through external passages. In a radiator heat is exchanged between an engine cooling fluid and air. In a heater core, heat is exchanged between an engine cooling fluid and air. In an evaporator, heat is exchanged between a refrigerant and air. In a condenser, heat is exchanged between a refrigerant and air.
A typical heat exchanger is a fin-tube type heat exchanger where the internal fluid flows through a plurality of tubes and the external fluid flows over the outside of the tubes. Fins are typically disposed between adjacent tubes in order to improve heat exchanger heat rejection by exposing multiple leading edge surfaces to the external fluid flow. The fins can include louvers which are formed with a twisting action of the central portion of the fin. This twisting action used to form the louvers limits the length of the louver to approximately 80% to 90% of the height of the fin. Heat exchanger performance is dependent on the effective length of the louver within the fin and thus it is advantageous to provide a louver with as large of a length as possible.
In addition, the twist forming of louvers causes a redirection of the external fluid as it passes over the louver. This redirection of the external fluid causes fluid pressure to drop which can decrease the total amount of the external fluid which passes through the heat exchanger thus adversely affecting its performance.